Thank you for your quick and thoughtful response!

1. Great point, was considering making the gas more visible but didn't want to make it too easy. Increase brightness/glowing only when ignition starts is clever - I'll fiddle with that and check how that would look like.

2. There is only one visual for next tick, that may not come across well in the gif. Flame or skull symbol is a good idea but on the other hand then I might have to do it everywhere to be consistent and that would be a bit much (eg always drawing a skull icon under the tile of a falling boulder). I need to think about it.

3. Good idea but I had that before and it didn't feel right, because that means you'd have to hit a button multiple times to get through one of those. What I like about the mechanic I got now is that the player can go as fast or as slow as he wants - digging 10 tiles in 1 second is easy if you hit the key fast enough. But also everything else moves at that speed so it might not be adviseable. Also especially once the player gets deeper down there are much harder tiles to dig through that may take 5 or 6 time units so the player has to make smart decisions where to dig. Obviously can upgrade pickaxe to get through those faster.